Heat exchanger



Jan. 2, 1968 w. l.. PRINGLE HEAT EXCHANGER 2 Sheets-Sheet l 1 Filed Aug. 19, 1965 vma ATTORNEYS W. L. PRINGLE Jan. 2, 1968 HEAT EXCHANGER Filed Aug. 19, 196s 2 SheetS-Sheet 2 WnLLl-AM LfPRm-GLE BY 95W ,JMA

i ATTORNEYS United States Patent O 3,361,198 HEAT EXCHANGER William L. Pringle, Grosse Pointe, Mich., assigner Eaton Manufacturing Company, a corporation of Ohio `Filed Aug. 19, 1965, Ser. No. 481,014 10 Claims. (Cl. 165-164) This invention relates to a heat exchanger used, for example, in motor vehicles, aircraft, marine and industrial applications requiring heat exchangers.

Heat exchangers have numerous functions in motor vehicles. For example, in order to cool hot water circulating in the engine block, the hot water is moved or circulated against :a wall having a high coefficient of heat transmission. A coolant, e.g. cold water, is moved or circulated against the other side of the wall. The hot and cold water will be cooled and heated, respectively, as heat is transmitted through the wall. This common wall through which the heat is transferred is one of the sirnplest forms of a heat exchanger.

It should be readily understood that by increasing the area of the 'heat transmitting wall surfaces, i.e. exposing more surface to the hot or cold water, more heat will be transferred. One if the problems encountered in designing a heat exchanger is increasing the area of the heat transmitting wall surfaces without making the heat exchanger bulky or cumbersome, or depending on intricate devices to increase the exposed surface area. Such poorly designed heat exchangers are costly to manufacture and being susceptible to damage are also costly to maintain.

This invention solves this problem by providing a high-ly improved heat exchanger Whose unique design provides increased wall surfaces for better heat transmission While further providing a unit which is economically manufactured and maintained.

Briefly stated then, this invention is in a heat exchanger comprising a body portion of uniform cross section and having several longitudinal passageways with means at each end of the body portion to direct fluids at different temperatures through the passageways in isolation from each other. The body portion is an elongated hollow tube having a plurality of longitudinally extending isolated passageways through which fluid is circulated, the passageways being formed by the outer walls of the tube and a plurality of partition or dividing walls longitudinally coextensive with the tube and extending inward-ly from the outer walls of the tube. A plurality of projections extending into t-he passageways are disposed on the dividing wall surfaces for increasing their exposed area. The projections include a plurality of ribs projecting from the wall surfaces, the ribs being Iadjacently disposed and longitudinally coextensive with the Walls.

The invention Will be better understood by having reference to the annexed drawings, wherein:

FIG. l is a side view of an embodiment of a heat exchanger of this invention;

FIG. 2 is a cross-sectional view of the body portion of the heat exchanger, the section being taken in the plane indicated by the line 2--2 of FIG. 1;

FIG. 3 is a cross-sectional View of a cap for sealing one end of the body portion, the section being taken in the plane indicated by the line 3-3 of FIG. 1

FIG. 4 is a cross-sectional view of the other cap for sealing the other end of the body portion, the section being taken in the plane indi-cated by the line 4 4 of FIG. 1; and

FIG. 5 is an enlarged section-al view of a typical partition wall in the caps, the section being taken in the plane indicated by the line 5-5 of FIG. 3.

Referring more particularly to the annexed drawings, there is shown a heat exchanger generally indicated at lll. The heat exchanger essentially comprises `a body por- ICC tion 11 having caps 12 and 13 mounted on and sealing its open extremities 14 and 15, respectively, by any suitable means, eg. bolts i6 and 17, respectively.

The body portion 11 (FIG. 2) is an elongated hollow tube, preferably, extruded from any suitable aluminum alloy.

A plurality of partition or divider walls 18-25 are disposed in the hollow tubular body lll and act as heat transmitting or common walls previously referred to. The partition walls lil-25 are longitudinally coextensive with the outer tubular walls 2629, and, preferably, radiate fro-m a hub 3u whose longitudinal axis coincides with the longitudinal axis of the tubular body 11.

A plurality of longitudinally extending passageways i-3% are formed by the tubular Walls 26-29 and the partition walls 18-25.

The passageways .3l-38 are isolated from each other by the partition walls lit-25 which act as common walls against which, for example, hot and cold fluid move as it circulates through adjacently disposed passageways, eg. passageways 31 and 32.

The heat exchanger body 11, preferably, has a uniform cross section throughout its length. Also, the passageways 31-38, preferably, have, equal cross-sectional areas in planes normal to the longitudinal axis of the heat exchanger body 1l.

A plurality of projections, eg. projections 39 and 40 on the partition wall 1S, are disposed on the partition and tubular wa-ll surfaces and extend into the passageways 3ft-3S for increasing the area of the wall surfaces exposed to the circulating fluid. The projections are in the forni of ribs projecting from the wall surfaces. The ribs are' adjacently disposed and are longitudinally coextensive with the partition and tubular walls. The ribs projecting from the wall surfaces provide a serrated surface giving the heat exchanger lil much improved and greater heat transmitting wall surfaces for greater exposure to the hot or cold fluid circulated in the passageways 31-38 in the tubular body 11.

The caps 12 and 13 (FIGS. 3 and 4) are preferably cast from any suitable aluminum alloy, and are used for directing the flow of fluid through the passageways 31-33 in the heat exchanger body l1.

A plurality of partition or divider walls 42-45 are formed within the cap l2 connecting passageway 31 With passageway 33, and passageway 35 with passageway 37. Passageways 32 and 34 are connected. through a surge tank 46 mounted on and integral with the cap 12. The surge tank 46 is utilized to relieve excess fluid pressure in the passageways 32, 34, 36 and 38.

A pair of hose connections 47 and 48 are formed in the cap 12 and communicate directly with. the passageways 38 and 36, respectively, and indirectly with the passage- Ways 32 and 34. The hose connections 47 and 4S are interchangeably used as an inlet and outlet for fluid, eg. hot water, circulated through the heat exchanger 10.

A plurality of partition walls Stb-53 are .formed in the cap 13 for connecting the remaining passageways. The partition wa-lls -53 connect passageway 32 with passageway 38, and passageway 34 with passageway 3o. The passageway 33 is connected with passageway 35 through a similar surge tank 54 mounted on and. integral with the cap 13. The surge tank 54 is utilized to relieve excess fluid pressure in the passageways 31, 33, 35 and 37.

The cap 13 is also provided with a pair of hose connections 55 and 56 which communicate directly with passageways 37 and 31, respectively, and indirectly with passageways 33 and 35. The hose connnections 55 and 56 are also interchangeably used as an inlet and outlet for fluid, eg. cold water, circulated through the heat exchanger 10.

The surge tanks 46 and 54 tare provided with openings 57 and 58, respectively, through which fluid, eg. cold water, is poured into the heat exchanger 10. Similar caps, eg. cap 59 are provided for sealing the openings S7 and 58 in the surge tanks 46 and 54, respectively. The cap 59 is provided with a restricted opening 60 through which excessive Huid pressure is emitted.

The marginal edges of the caps 12 and 13 adjacent the abutting heat exchanger extremities 14 and 15, respectively, are provided with a recess in which is seated a pliable `seal for sealing coaction with the heat exchanger body 11 to keep fluid from leaking between it and the caps 12 and 13. For example, a pliable seal 61 (FIG. 1) is disposed in the recess 62. of the Wall 63 of cap 13.

Similar seals are provided in recesses formed in the partition walls 42-45 and 50-53 of caps 1?. and 13, respectively. For example a pliable seal 64 (FIG. 5) is provided in the recess 65 of partition wall 43 of cap 12, for sealing coaction with the adjacent partition wall 18 of the heat exchanger body 11. The pliable seals keep the fluid from filtering into adjacent passageways as it is circulated through the heat exchanger 10.

The heat exchanger is mounted within a motor vehicle or aircraft by any suitable mounting means, e.g. mountings 66 and 67 on caps 12 and 13, respectively.

The capacity of the heat exchanger is largely dependent upon the length of its body, the number of partition walls formed therein, and the ribs projecting from the partition walls. Because of these features, the size of the heat exchanger relative to its capacity is comparatively small and compact. The passageways in the heat exchanger body in conjunction with the passageways in the two caps, provide a pair of continuous lengthy passageways or independent fluid circuits through which liuid at different temperatures is circulated. For example, hot water from an engine block is circulated through alternate passageways 31, 33, and 37, and cooled by comparatively cold water circulated through the adjacent alternate passageways 32, 34, 36 and 38.

The heat exchanger body 11 is extruded from any suitable aluminum alloy in continuous lengths which are then cut to appropriate sizes depending upon the capacity of the heat exchanger desired. In this manner the cost of manufacturing the heated exchanger is `greatly reduced.

Thus, there has been provided a highly improved heat exchanger for use in automotive vehicles and the like. The heat transmitting surfaces of the heat exchanger have been increased by providing a plurality of ribs projecting from the walls of the heat exchanger. T he capacity of the heat exchanger has been greatly increased by providing the ribs which are readily formed in the process for extruding the heat exchanger body.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or the equivalent of such, be employed.

1t is, therefore, particularly pointed out and distinct-ly claimed as the invention:

1. A heat exchanger comprising in combination an extruded hollow body having an outer wal'l and a plurality of elongated relatively thin, partition walls within said body and coextensiveand integral with said outer wall, said walls terminating at the outer ends of said body to form continuous longitudinally extending passageways with said outer wal-l, said body having identical cross-sections at all locations normal to the longitudinal axis thereof, the cross-sectional area of the passageways formed by said partition walls exceeding the cross-sectional area of the partition walls, cap means coacting with the outer ends of said walls, means forming with said passageways and cap means at -least two independent fluid circuits, and inlet and outlet means in communication wit-h each tluid circuit.

2. A heat exchanger as claimed in claim 1 in which said partition walls include longitudinally formed ribs projecting from the partition walls into the passageways.

3. A heat exchanger as claimed in claim 1 in which longitudinally formed ribs project from the walls of the tubular body into the passageways.

4. A heat exchanger as claimed in claim 1 in which a surge chamber is connected to at least one end cap and communicates with one of said fluid circuits.

5. A heat exchanger as claimed in claim 1 in which seal means are provided between the end caps and the body forming a iluid tight connection therebetween.

6. A heat exchanger as claimed in claim 1 in which a longitudinal section through any portion of said body is delined by mutually parallel lines.

7. A heat exchanger as claimed in Iclaim 1 in which any two adjacent passageways are formed in part by a common partition wall.

8. A heat exchanger as claimed in claim 7 in which at least someof said partition walls are joined along at least one common linear line of juncture which |line is parallel to the longitudinal axis of the body.

9. A heat exchanger as claimed in claim 1 in which said inlet and said outlet means are dened in said cap means.

10. A heat exchanger comprising in combination an extruded hollow body having an outer Wall having a pl-urality of partition walls coextensive and integral with said outer wall within said body forming continuous longitudinally extending passageways, said body having identical cross-sections at all locations normal to the longitudinal axis thereof, cap means coacting with the outer ends of said body including divider walls forming with said passageways at least two independent Huid circuits, and inlet and outlet means in said cap means in communication with each iiuid circuit.

References Cited UNITED STATES PATENTS 459,908 9/1891 Hogan 165-164 X 822,545 6/1906 McLaughlin 165-164 X 2,019,351 10/1935 Lathrop 165-165 2,672,131 3/1954 Wood 16S-134 X 2,895,508 7/1959 Drake 165-109 X 2,912,749 11/1959 Bauernfeind et al. 29-157.3 3,173,482 3/1965 Allender 165-174 3,182,380 5/1965 Oddy 29-157.3

FOREIGN PATENTS 539,529 9/1941 Great Britain. 471,475 5/1952 Italy.

ROBERT A. OLEARY, Primary Examiner.

MEYER PERLIN, Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

1. A HEAT EXCHANGE COMPRISING IN COMBINATION AN EXTRUDED HOLLOW BODY HAVING AN OUTER WALL AND A PLURALITY OF ELONGATED RELATIVELY THIN, PARTITION WALLS WITHIN SAID BODY AND COEXTENSIVE AND INTEGRAL WITH SAID OUTER WALL, SAID WALLS TERMINATING AT THE OUTER ENDS OF SAID BODY TO FORM CONTINUOUS LONGITUDINALLY EXTENDING PASSAGEWAYS WITH SAID OUTER WALL, SAID BODY HAVING IDENTICAL CROSS-SECTIONS AT ALL LOCATIONS NORMAL TO THE LONGITUDINAL AXIS THEREOF, THE CROSS-SECTIONAL AREA OF THE PASSAGEWAYS FORMED BY SAID PARTITION WALLS EXCEEDING THE CROSS-SECTIONAL AREA OF THE PARTITION WALLS, CAP MEANS COACTING WITH THE OUTER END OF SAID WALLS, MEANS FORMING WITH SAID PASSAGEWAYS AND CAP MEANS AT LEAST TWO INDEPENDENT FLUID CIRCUITS, AND INLET AND OUTLE AMEANS IN COMMUNICATION WITH EACH FLUID CIRCUIT. 